1. Technical Field
The present invention relates to a driving method of an electrophoretic display device.
2. Related Art
In this type of electrophoretic display device, in regard to each of a plurality of pixels, an image is displayed by moving the electrophoretic particles through application of a driving voltage to, for example, an electrophoretic layer including white and black electrophoretic particles interposed between a pixel electrode and a common electrode. Additionally, it is possible to perform multitone display where a halftone (for example, gray) is displayed by changing the period of time when a driving voltage is applied to the electrophoretic layer for each pixel. In order to perform multitone display with high precision, it is necessary to control the application time of a driving voltage with high precision.
For example, in JP-A-2007-79170, a technology is disclosed for preventing an uneven display of color in a case of switching between display colors in an electrophoretic display device, by changing the application time of a driving voltage in accordance with the continuous display time of a display color displayed before switching.
In this type of electrophoretic display device, there is a technical problem in that it is difficult to perform multitone display with high precision which requires controlling of the application time of the driving voltage with high precision. In particular, it is difficult to control the application time of the driving voltage so that the halftone to be displayed is accurately displayed in each pixel since the motion of the electrophoretic particles when applying the driving voltage varies with the environment, such as temperature and humidity. As a result, an accurate display is difficult when the number of gradation levels is increased.